Disabled and need help on snapper pro 36 /48 or hustler sport

Hello to all of you out there on lawnsite. I've been lurking here for a few weeks scouring the site for info. I am partially disabled but generally in decent health except for a muscle disease that although in remission has left me having to stop at least twice during my mowing session of only about 1/3 acre grass. I have a lot of time on my hands so I want to mow my own grass and want a ZTR to be efficient. My lawn is slightly sloped in front and multi-level in the back with numerous stone walls,drop offs and landscape edging. I'll probably still have to use my 21" walk behind to mow an incline that descends 15 feet from top to bottom. It progresses from 15 degrees at the north side to about 30 degrees at the south at the back of my yard so is fairly steep at the SE corner.Neither a cheap JD lawn tractor nor my neighbor's dixon ZTR could climb it. I have ruled out a WB with sulky.
I at first wanted a CC z force s 46 but felt this would be a decision I might regret after doing the research. I have two decent dealers nearby selling snapper pro and hustler/cub cadet. I thought the hustler sport 42" looked good except the hydrogears (EZT). Snapperpro looks to be a good value. Looking at a 36" with kaw 19 hp and 3100 hydros. I would rather have a 36-42 inch deck instead of a 48 so I don't have to repeatedly hear my wife ask why the mower takes up so much garage space.
The snapper guy is a good dealer.He said the less expensive (cheaper?)B&S pro engine would be good enough for my purposes instead of the kaw if I wanted to save some money. The Hustler/Cub Cadet guy is good too and said even a hustler was overkill. His advice was just get a cub rzt s 42 instead, especially if my family wants to use it because the steering wheel would be easy to use. I'm pretty sure he will sell me a more expensive machine if I insist though. I also have access to a pull behind plug aerator which seems to be influencing my decision on the hydrogears and thus the desire for more commercial specs. I want a machine that will last a long time (i'm 52 yo). I hate getting things fixed and would rather make the best attempt at quality but at a reasonable price point. I want to spend less than 5k but would be willing to spend half that much if this is really all I need considering the size of my lawn. I am perfectly too aware of the possibility I am overdoing and overthinking this but I plead inexperience and lack of practical knowledge. Also, is aerating flatter areas of my lawn a stupid idea even with a good ZTR? Thanks for any help you can give me and I am open to any suggestions.